In the prior art, a known safe unlocking machine collects currency (coins, bills, and the like) from safes of fareboxes (refer to, for example, patent document 1). Each safe includes a safe main body, which stores currency, and a lock-incorporated safe door, which closes an opening of the safe main body through which the currency is accessed. The safe is attached to a farebox main body in a removable manner. The safe door is closed and locked when the safe is removed from the farebox. When the safe unlocking machine collects the currency from the safe, for example, the safe is turned upside down and set in the safe unlocking machine. The safe unlocking machine unlocks the safe door. By moving only the safe main body while keeping the safe door at the same position, the currency falls from the safe into a currency container of the safe unlocking machine. This task is performed on each safe. The safe unlocking machine stores currency from a plurality of safes in a centralized manner.
The currency container is movable into and out of the safe unlocking machine main body so that the currency, which has been collected in a centralized manner, can be removed. When resetting the currency container in the safe unlocking machine main body, the currency container may be improperly set in a safe unlocking machine main body that differs from the one to which the currency container was attached to before. For example, patent document 2 discloses a technique for performing verification between the safe unlocking machine main body and the currency container. In the technique of patent document 2, the safe unlocking machine main body and the currency container are connected by an electrical contact to perform encryption communication. When the container unit is correctly recognized, currency collection in the container unit is permitted.